As does in __sctp_connect(), when checking addrs in a while loop, after
get the addr len according to sa_family, it's necessary to do the check
walk_size + af->sockaddr_len > addrs_size to make sure it won't access
an out-of-bounds addr.
The same thing is needed in selinux_sctp_bind_connect(), otherwise an
out-of-bounds issue can be triggered:
[14548.772313] BUG: KASAN: slab-out-of-bounds in selinux_sctp_bind_connect+0x1aa/0x1f0
[14548.927083] Call Trace:
[14548.938072] dump_stack+0x9a/0xe9
[14548.953015] print_address_description+0x65/0x22e
[14548.996524] kasan_report.cold.6+0x92/0x1a6
[14549.015335] selinux_sctp_bind_connect+0x1aa/0x1f0
[14549.036947] security_sctp_bind_connect+0x58/0x90
[14549.058142] __sctp_setsockopt_connectx+0x5a/0x150 [sctp]
[14549.081650] sctp_setsockopt.part.24+0x1322/0x3ce0 [sctp]
Fixes: d452930fd3b9 ("selinux: Add SCTP support")
Reported-by: Chunyu Hu <chuhu@xxxxxxxxxx>
Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
---
security/selinux/hooks.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index f0e36c3..dac9bdb 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -5120,6 +5120,9 @@ static int selinux_sctp_bind_connect(struct sock *sk, int optname,
return -EINVAL;
}
+ if (walk_size + len > addrlen)
+ return -EINVAL;
+
err = -EINVAL;
switch (optname) {
/* Bind checks */
--
2.1.0
